package com.chentf.reggie.controller;

import com.chentf.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * @author chentengfei
 * @desc 文件上传和下载
 * @date 2022-09-11 22:59:03
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /***
     * 文件上传
     * @author chentengfei
     * @date 2022/9/11 23:15
     * @param file
     * @return com.chentf.reggie.common.R<java.lang.String>
     */
    @PostMapping("/upload")
    public R<String> update(MultipartFile file){ //file属性名对应页面name="file"属性
        //file是一个临时文件,需要转存到指定位置,否则本次请求完成后临时文件会删除
        log.info(file.toString());

        //原始文件名
        String originalFileName = file.getOriginalFilename(); //abc.jpg
        String suffix = originalFileName.substring(originalFileName.lastIndexOf("."));

        //使用UUID重新生成文件名,防止文件名称重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix; //dfadfdfd.jpg

        //创建一个目录对象
        File dir = new File(basePath);
        //判断当前目录是否存在
        if(!dir.exists()){
            //目录不存在,需要创建
            dir.mkdirs();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        }catch (IOException e){
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    /***
     * 文件下载
     * @author chentengfei
     * @date 2022/9/11 23:15
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download (String name, HttpServletResponse response){
        try {
            //输入流,通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流,通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}
